DescriptionAdvanced high-strength steels (AHSS) possess great combination of mechanical properties such as ductility, strength, toughness and good crash behavior. The utilization of AHSS in the automotive industry opens up new possibilities for reducing the weight of cars and, therefore, for reducing greenhouse gas emissions. However, the proneness of AHSS to hydrogen embrittlement counteracts the widespread and safe application of these steels. During steelmaking, manufacturing and service the pick-up of hydrogen can cause the degradation of mechanical properties and can lead to time-delayed fracture of AHSS components. Testing the susceptibility of materials to hydrogen embrittlement (HE) has been challenging. Published results of HE tests are sometimes contradictory, because testing procedures are influenced by many different factors, such as sample geometry, testing speed, mechanical properties, microstructure, time, etc. Therefore, the present work aims to improve the understanding of HE testing and to optimize existing testing procedures. Three dual phase (DP) steels with different ultimate strengths were experimentally evaluated with respect to their HE behavior. Controlled electrochemical hydrogen charging combined with slow strain rate tensile testing (SSRT) was conducted. The influence of the sample geometry was studied by testing smooth as well as notched samples with different notch radii. Mathematical modeling was used to determine unified correlations between testing parameters and results. Hydrogen concentrations inside the samples were measured using thermal desorption spectroscopy (TDS). Furthermore, the procedure of HE testing was accompanied by diffusion-mechanical finite element (FE) simulations to improve the understanding of the simultaneous effect of internal hydrogen diffusion, hydrogen accumulation at the notch and mechanical loading.
|Period||13 Sept 2021 → 17 Sept 2021|
|Event title||2021 European Congress and Exhibition on Advanced Materials and Processes : EUROMAT 2021|
|Degree of Recognition||International|
Fields of Expertise
- Advanced Materials Science